458 SOCOM AR-15

[SideShow Bob]

Brass from 300 gr. rated at 1950 FPS. A little over pressure ?




Sent from my ass using re-fried beans.

[Dave]

Doesn't look too bad, not sure how it would affect the ability to reload it though. Maybe you should post it or a link to here in the reloading thread to get some extra opinions. The 300 gr rounds I have are rated to 1800 fps instead of 1950.

The others I have are 400 gr, and all of mine are JHP. I have been thinking about the heavier ones as hunting rounds, but last night I got to thinking that most 400 gr+ rounds are slower (1500 FPS range) and I was worried that this might affect accuracy at longer distances since it might drop more past 100 yards than a faster 300 gr round. Anyone have thoughts on it?

[davsel]

Just using a quick online ballistics calculator,
300g, .302bc, 1800fps = -12.5" at 200 yards with a 100 yard zero
400g, .302bc, 1500fps = -18.6" at 200 yards with a 100 yard zero

Personally, I don't anticipate needing more than 300g to take down anything in North America within 200 yards.
I plan to use the >350g bullets for primarily subsonic purposes.

[Dave]

Just using a quick online ballistics calculator,
300g, .302bc, 1800fps = -12.5" at 200 yards with a 100 yard zero
400g, .302bc, 1500fps = -18.6" at 200 yards with a 100 yard zero

Personally, I don't anticipate needing more than 300g to take down anything in North America within 200 yards.
I plan to use the >350g bullets for primarily subsonic purposes.

Yeah, that's a hell of an extra drop at 200 yards. Might rethink my choices. Been getting different rounds mostly because I've just bought as I get emails saying something in .458 is available.

What calculator are you using? Is it online or one you have downloaded?

[MarkCO]

At least with the .450BM (should be similar) as long as I keep about 1300 fps with the heavies, the accuracy stays pretty much straight MOA. I hope to be tossing 300s and 320s arond 2400 to 2500 or so in a few weeks once I get the .450 BM/C all dialed in.

[davsel]

I just Googled "ballistics calculator" and chose this one:
http://www.federalpremium.com/ballistics_calculator/

I was just guessing on the bc for those two rounds.
It would be an even greater spread if you are using pointed 300g (Barnes Tac-TX) vs. flat nosed 400g.

[davsel]

I loaded up my first 10 rounds last night and plan to set them off this evening.
Hodgdon BL-C(2) is the only powder I have on hand that I could even find loading data for the .458 SOCOM.
I also only have standard large pistol primers - not magnum.

I extrapolated from a few different charts and came up with this as a first go:

48g BL-C(2)
CCI 300
350g Hornady InterLock flat nose

[SideShow Bob]

Maybe you should post it or a link to here in the reloading thread to get some extra opinions.

Already did awhile back, it didn't get very many responses. I was just wondering if this was an RRA bolt/upper problem, or just an over pressure problem.

https://www.ar-15.co/threads/116051-...d-Gouged-Brass

[davsel]

Now, that was fun!
Just lobbed 3 rounds down range, got the scope sighted in.
Ran flawless, no signs of over-pressure.
I'll save the rest for tomorrow when my buddy brings up his chronograph.
I like it!

[davsel]

Well, upon further inspection, I may have found an issue with this $300 billet upper.
Here's a copy of what I just sent to Wilson Combat:

I recently purchased your .458 SOCOM Billet upper. I fired 3 rounds today and upon inspection, I noticed a couple of silver specks in the top of the ejection port. I scraped at them with my fingernail, and they got bigger.

Does this billet upper have machining done to the ejection port after anodizing and then simply painted black?

I'll wait to see what they say before getting excited.
I assumed the .458 billet upper they are selling would have been machined before anodizing - they even have ".458 SOCOM" engraved into the left side of it.
I even have one of Jay's uppers just sitting on a shelf - didn't want to have it machined and then painted over.